The article gives one example and says it was a "few" accounts. Why ban all of them?

They weren't all banned. There's still at least a couple of these NPC satire accounts floating around out there now.

If you are misled about when the vote is by a tweet from an account with a wojak avatar, it's probably for the better of mankind if you don't vote... or procreate.

Eugenics is bunk and low information voters are still entitled to their representation and votes.